Structure of a single-part elastic waist support

ABSTRACT

An elastic waist support is installed between a back frame and a mesh member of a chair, and can be adjusted in height; the back frame consists of a front frame part, and a rear frame part, which are firmly joined together; the mesh member covers a front side of the front frame part with a periphery thereof being sandwiched between the front and the rear frame parts; the back frame has two opposite supporting extensions protruding from inward sides of two longitudinal portions thereof; each of the supporting extensions has a guiding groove thereon; the waist support has two joining protrusions thereon, and it is joined on the back frame with the joining protrusions being respectively embedded in the guiding grooves.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to a single-part elastic waist support, more particularly one, which is positioned between a mesh member and a frame of a back of a chair, and can change shape according to the position and shape of the sitter's back for the sitter to be steady and comfortable.

2. Brief Description of the Prior Art

Chair backs are usually made by means of wrapping leather or cloth around wooden or plastic board-shaped materials. Such chair backs are likely to make the sitters feel hot and uncomfortable, especially in summer, because air cannot travel through them. Another chair back is available, which is comprised of a frame, and a highly elastic mesh secured over a space encompassed by the frame. Such mesh chair back allows air to travel through it therefore the sitter won't feel uncomfortably hot at his back even if he has been sitting on the chair for a long length of time in summer. However, the mesh part of the chair back can change shape easily, and in turn it can't support the sitter's back in a proper position when the sitter leans back against it. Consequently, the sitter is prone to have sore waist and painful back after having been seated in the chair for a long length of time.

Referring to FIG. 6, yet another chair back 4 is provided to overcome the above-mentioned problem. The chair back 4 consists of a board part 41, and a mesh member 42, and a waist support 5 is joined in the chair back 4. The waist support 5 consists of a front pad, and a main part, which has joining protrusions 51 on a rear side, and gripping portions 52 at two ends thereof. The mesh member 42 consists of a frame 421, and a mesh secured over a space encompassed by the frame 421. The board part 41 has longitudinal guide grooves 411 on a front side thereof. Sleeves are sandwiched between a periphery of the board part 41 and the frame 421 of the mesh member 42, and threaded fixing elements are passed through the sleeves to secure the mesh member 42 to the board part 41. The waist support 5 is positioned between and closely in touch with the board part 41 and the mesh member 42 with the joining protrusions 51 being embedded in the guide grooves 411, and with the grip portions 52 sticking out from left and right sides of the chair back 4; thus, the waist support 5 can be adjusted in height.

The above chair back can support a sitter's back in a proper position owing to the waist support. However, the chair back has the following drawbacks: the waist support comprises two separate parts, the front pad and the main part, and therefore takes some labor and time to assemble. Consequently, the manufacturing cost of the waist support is relatively high. Secondly, the waist support is formed with holes for air to travel through. Thirdly, the waist support and the mesh member are a distance apart and have different curvatures. Therefore, the waist support can't support a sitter's waist effectively.

Therefore, it is a main object of the present invention to provide an improvement on a waist support of a chair to overcome the above problems.

SUMMARY OF THE INVENTION

A waist support in accordance with an embodiment of the present invention has a relatively high elasticity, and has a joining protrusion near each of two ends thereof. The chair includes a back frame, and a mesh member on a front of the back frame. The back frame consists of front and rear frame parts, which are firmly joined together with a periphery of the mesh member being sandwiched between them. The back frame has two opposite supporting extensions, each of which has a guiding groove thereon. The waist support is positioned between the mesh member and the back frame with the joining protrusions being embedded in the guiding grooves of the back frame. Therefore, the elastic waist support will change shape to be closely in touch with the sitter's waist when the sitter presses his back against the mesh member.

Moreover, the waist support has several holes, which can increase the elasticity of the waist support, and allow air to travel through.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood by referring to the accompanying drawings, wherein:

FIG. 1 is an exploded perspective view of a waist support in the present invention,

FIG. 2 is a sectional view of the waist support in FIG. 1,

FIG. 3 is a front view of a chair in the present invention, taken when the waist support is being adjusted in position (1),

FIG. 4 is a front view of a chair, taken when the waist support is being adjusted in position (2),

FIG. 5 is a perspective view of the chair in the invention, and

FIG. 6 is a sectional view of the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, a preferred embodiment of a chair back of the present invention consists of a back frame 1, a mesh member 2, and an elastic waist support 3.

The back frame 1 consists of a front frame part 11, and a rear frame part 12, which have protruding portions and receiving cavities thereon, and are joined together with the protruding portions being embedded in the receiving cavities. The mesh member 2 is positioned over a front side of the back frame 1, and fixed in position with a periphery thereof being sandwiched between the front and the rear frame parts 11 and 12.

The rear frame part 12 of the back frame 1 has two opposite supporting extensions 121, which protrude from inward sides of two longitudinal parts thereof. Each of the supporting extensions 121 has a guiding groove 122 thereon.

The elastic waist support 3 includes only one part, and has a joining protrusion 31 near each of two ends thereof, which is shorter than the guiding grooves 122 of the rear frame part 12. The elastic waist support 3 is positioned between the mesh member 2 and the front frame part 11 of the back frame 1, and joined on the rear frame part 12 of the back frame 1 with the joining protrusions 31 being embedded in the guiding grooves 122 of the supporting extensions 121 respectively.

In assembly, referring to FIGS. 2 to 5, first the elastic waist support 3 is positioned on a front side of the front frame part 11 and joined on the rear frame part 12 by means of making the joining protrusions 31 embedded in the guiding grooves 122 of the supporting extensions 121 of the rear frame part 12. Next, the mesh member 2 is positioned over the front frame part 11 of the back frame 1, and the front and the rear frame parts 11 and 12 are joined together to sandwich a periphery of the mesh member 2 between them; thus, the elastic waist support 3 exists between the mesh member 2 and the front frame part 11 of the back frame 1. Therefore, the elastic waist support 3 can be moved up and down with the joining protrusions 31 changing position within the guiding grooves 122 of the rear frame part 12. In other words, the elastic waist support 3 can be adjusted in height according to the sitter's need. Moreover, because the waist support 3 and the mesh member 2 are elastic, they can change shape to be closely in touch with the sitter's waist when the sitter rests his back on the chair back; thus, the sitter will be steady, secure and comfortable on the waist support 3.

Furthermore, the elastic waist support 3 has several holes 32 thereon, which can increase the elasticity of the waist support 3, and allow air to travel through the waist support 3; the holes 32 together form a design, and can be regularly or irregularly arranged.

From the above description, it can be seen that the present invention has the following advantages over the prior art:

1. The elastic waist support includes only one part, and can be easily joined on the back frame of the chair by embedding the joining protrusions in the guiding grooves formed on the back frame. Therefore, it takes relatively low material and labor cost to manufacture the waist support of the invention.

2. The elastic waist support can change shape to be closely in touch with the sitter's waist together with the mesh member when the sitter presses his back against the mesh member. Therefore, the sitter will be very steady, secure and comfortable on the chair with his waist being propped against the waist support.

3. The elastic waist support has several holes thereon, which can increase the elasticity of the waist support, and allow air to travel through the waist support. 

1. Structure of a single-part elastic waist support, the elastic waist support being installed between a back frame and a mesh member of a chair; the back frame having two opposite supporting extensions protruding from inward portions thereof; each of the supporting extensions having a guiding groove thereon; the elastic waist support having two joining protrusions thereon; the elastic waist support being joined on the back frame with the joining protrusions being inserted in the guiding grooves respectively; the elastic waist support having a plurality of holes thereon.
 2. The single-part elastic waist support structure as claimed in claim 1, wherein the back frame consists of a front frame part, and a rear frame part, and the mesh member covers a front of the front frame part with a portion thereof being sandwiched between the front and the rear frame parts. 